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speedometer calibration

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43K views 16 replies 10 participants last post by  Ryno_WJ  
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#1 ·
I just put larger tires on my 2000 WJ. How do I recalibrate the speedo? It has the quadratrac II transfer case. It is as simple as replacing a gear in the tcase? Do I have to pay the dealer to do it because it is computer related?

Thanks
 
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#5 ·
im almost positive thats for ZJs only. i had to do it in my old ZJ and it was a little plastic gear thingy that swapped out in like 20 min.

never heard of this for the WJ. isnt it done electronically?
 
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#6 ·
Yeah, I know for a fact that's for ZJs because I've done mine before using that table. It just struck me odd that it was brought up for a WJ...I think it's electronic too...

If my memory serves me right, something with the Anti-Lock Brake Sensors?
 
#7 ·
The WJ gets its speed signal from the ABS tone rings on the axle shafts not the TC. Therefore, the aforementioned T-case speedo gear swap does not apply.

What size tires did you put on? The dealer can adjust your speedo to the largest tire size that came stock (maybe a little bit more, IDK) to get it a little bit closer, or your other option is the Superlift Speedo Recalibrator http://www.4wheelerssupply.com/catalog/product_info.php/products_id/1762
 
#8 ·
A 31" tire and my speedo is perfectly calibrated to my GPS. :2thumbsup:

But rumor is that the Odometer will be reading low.:2thumbsup:
 
A
#11 ·
So I took it to the Local Jeep Dealership, and they tried to re calibrate the speedometer for my new tires (245/70/17) and after 2 hours they came back saying they couldn't do it. They said the Pinion would only go so low, then reset to the factory default. They apparently tried multiple times...

He told me they set it to the lowest they could get it (which is less than half of what it should be with the new tires) and didn't charge me anything for it. I tried using my GPS to see how much better it was, but it still looked to be about 3mph off.

I don't care about the speedometer as much as the odometer displaying the wrong miles.

Any thoughts? Its not like I upgraded to HUGE tires, but even if I did...come on its Jeep...you would think it should be possible??
 
#12 ·
Hello All.

I have the same problem.

I have a 2004 WJ Overland and have installed 33" tires. I need to reprogram the speedometer. How can i calculate the correct Ring/pinion and tire size setup?

In the dealer they can only adjust to some tire sizes a little larger than stock, but if i change to the larger tire size available in the computer and modify also the R&P Ratio maybe i can set up to the correct spedometer.

Anybody knows the available options for tires and R&P in the programmer?

Thanks

Mariano
 
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#13 ·
Reviving this thread in hopes someone knowledgeable can chime in...I just put 265/75R16 on my WJ Limited. I found this thread that states the electronic speedo on a WJ uses the ABS tone ring signal to generate the speedometer output.

Question is can the computer be programmed to adjust for the slower turning tires at a given speed? e.g. is the WJ computer programable to set a different parameter for rear axle ratio or ? to trick it into reading the ABS signal and generating an accurate speed output?

I saw the link for an inline translator, just trying to fix the speedo on the cheap.
 
#14 ·
Ryno_WJ said:
Reviving this thread in hopes someone knowledgeable can chime in...I just put 265/75R16 on my WJ Limited. I found this thread that states the electronic speedo on a WJ uses the ABS tone ring signal to generate the speedometer output.

Question is can the computer be programmed to adjust for the slower turning tires at a given speed? e.g. is the WJ computer programable to set a different parameter for rear axle ratio or ? to trick it into reading the ABS signal and generating an accurate speed output?

I saw the link for an inline translator, just trying to fix the speedo on the cheap.
Click to expand...
a dealer can fine tune the speedo but huge differences can not be adjusted for. The only thing that will effect speedo on a wj is tire size, it does not care about transmission, tc or gear ratios since speed comes form the abs tone ring at the end of the axle. The only real fix is the programmable devices that go for about $250.
 
#16 ·
It can be done, It was done to mine for $20 at the dealer, the setting under the drb tool is under the ABS section, I can't remember the exact setting (it's like 704 or 706 or something but if they set it at it's highest revolution it works perfect for 31" tires on a WJ. Problem is when you go higher it will still be off, but not by as much as before. Mine is still set for 31" tires in my computer, but with the 4.10's installed the 33's make the speedo perfect again.
 
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#17 ·
Sounds like you are talking about revs/mile rating of a tire...705 is about the value for a 245/70R16 (29.5" tire) that came stock on my Limited...a BFG AT 265/75R16 (~31.7") that I installed is 656 revs/mile at 45 mph (SLR changes at speed as centrifugal force makes the tire diameter larger at higher speeds).

So now I just need to find a Heep dealer that is willing to tinker with the drb tool...too bad there are only a few left in Portland Metro with the recent contraction of the domestic automotive industry.

Thanks guys! I like the sounds of ~$20 using stock equipment much better than $250 with some black box that may malfunction down the road.
 
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